1. Field of the Invention
This invention relates to translucent soap bars and methods for production thereof. More particularly, this invention relates to making milled or machine finished, translucent soap bars which contain synthetic detergents, i.e., "combo-bars".
2. Prior Art
Transparent soap bars (the ultimate translucent soap bar), and methods for their manufacture, have been known for many years. Being costly to manufacture, they have been generally regarded as luxury items, and their properties have been equated with high purity and neutrality (although they may actually contain free alkali or free fatty acids). Such products have been used almost exclusively for toilet articles, i.e., bathing, hand, and face washing soaps, etc.
Numerous transparent soaps have been formulated. A classic method involves the low temperature saponification of fats and oils predissolved in warm alcohol, water, and glycerine, followed by evaporation of part of the alcohol/water azeotrope. Another common technique is based upon the addition of a polyhydric alcohol, such as glycerol, glycol, sugar or the like to a "neat soap" or semi-boiled soap, or to soap prepared by the cold process technique. Still another method consists of dissolving soap in alcohol to solubilize certain components and then distilling off most of the alcohol.
U.S. Pat. No. 3,562,167 to Kamen describes a transparent soap formed from a combination of soap, polyhydric alcohol, and as a surface-active agent, a polyalkoxy ether of an alkylphenol.
U.S. Pat. No. 3,903,008 to Deweever et al. describes the formulation of a transparent soap by the combination of soap, polyhydric alcohols, and a quaternized dihydroimidazole detergent.
U.S. Pat. Nos. 3,793,214 and 3,926,828 to O'Neil et al. describes transparent soaps produced using branched chain fatty acids. U.S. Pat. No. 3,864,272 to Toma et al. describes the use of a rather complicated, elaborate mechanical method of working the soap, i.e., spray drying followed by mechanical working.
A method of formulating a transparent soap is disclosed in U.S. Pat. No. 2,820,768 where a sodium soap made from tallow, coconut oil, and caster is mixed with a triethanolamine soap of stearic acid and oleic acid and an excess of the amine.
U.S. Pat. No. 4,290,904 to Poper et al describes a transparent low alkalinity bar soap based on a tetrakis (hydroxyalkyl) ethylene diamine.
One of the disadvantages of these prior art transparent soap bars is that they form a scum in hard water. In order to overcome this problem with soaps, not only in transparent soaps, synthetic detergents were developed. It has been found, however, that when these synthetic detergents are added to the typical transparent soap to form what is called a "combo-bar" (i.e., a combination of synthetic detergent and soap), that the bar is no longer transparent. To the Inventors' knowledge, no one to date has made a transparent bar using a synthetic detergent and a soap having the enhanced transparency, clarity, color, and purity of the soaps as described and claimed in Applicant's parent application, U.S.S.N. Ser. No. 07/019,358, now U.S. Pat. No. 4,851,147 nor has anyone used the solubilization system described and claimed therein for cosmetic ingredients.
Additionally, to the inventors' knowledge, no one to date has made a translucent, milled or machine finished, or extruded bar using a synthetic detergent and a soap having the enhanced translucency and enhanced gritlessness of the soaps described and claimed herein.
Further, U.S. Pat. No. 3,741,911 to Shane described certain alkyl-aryl polyoxyalkylene carboxylic acids and derivatives thereof for use as a surfactant in detergent compositions. The entire disclosure of this patent is incorporated herein by reference.
Applicant has discovered that when certain alkanolamines, preferably when used in conjunction with these alkyl-aryl polyoxyalkylene carboxylic acids and preferably utilized in conjunction with a combination of a synthetic detergent and a soap that, surprisingly and unexpectedly, a translucent milled "combo-bar" may be produced.